refactor(forms): remove registerWidget and use event instead

Each widget (ng-model directive) emits $newFormControl event instead of getting hold of parent form
and calling form.registerWidget(this);

src/directive/form.js

@@ -33,7 +33,7 @@ function FormController($scope, name) {
   $scope.$on('$destroy', function(event, widget) {
     if (!widget) return;
 
-    if (widget.widgetId) {
+    if (widget.widgetId && form[widget.widgetId] === widget) {
       delete form[widget.widgetId];
     }
     forEach(errors, removeWidget, widget);
@@ -60,6 +60,12 @@ function FormController($scope, name) {
     form.pristine = false;
   });
 
+  $scope.$on('$newFormControl', function(event, widget) {
+    if (widget.widgetId && !form.hasOwnProperty(widget.widgetId)) {
+      form[widget.widgetId] = widget;
+    }
+  });
+
   // init state
   form.dirty = false;
   form.pristine = true;
@@ -95,26 +101,6 @@ function FormController($scope, name) {
   }
 }
 
-/**
- * @ngdoc function
- * @name angular.module.ng.$compileProvider.directive.form.FormController#registerWidget
- * @methodOf angular.module.ng.$compileProvider.directive.form.FormController
- * @function
- *
- * @param {Object} widget Widget to register (controller of a widget)
- * @param {string=} alias Name alias of the widget.
- *                        (If specified, widget will be accesible as a form property)
- *
- * @description
- *
- */
-FormController.prototype.registerWidget = function(widget, alias) {
-  if (alias && !this.hasOwnProperty(alias)) {
-    widget.widgetId = alias;
-    this[alias] = widget;
-  }
-};
-
 
 /**
  * @ngdoc directive

src/directive/input.js

@@ -750,8 +750,8 @@ var inputDirective = [function() {
  * @description
  *
  */
-var NgModelController = ['$scope', '$exceptionHandler', 'ngModel',
-    function($scope, $exceptionHandler, ngModel) {
+var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel',
+    function($scope, $exceptionHandler, $attr, ngModel) {
   this.viewValue = Number.NaN;
   this.modelValue = Number.NaN;
   this.parsers = [];
@@ -762,6 +762,7 @@ var NgModelController = ['$scope', '$exceptionHandler', 'ngModel',
   this.valid = true;
   this.invalid = false;
   this.render = noop;
+  this.widgetId = $attr.name;
 
 
   /**
@@ -920,26 +921,22 @@ var ngModelDirective = [function() {
     inject: {
       ngModel: 'accessor'
     },
-    require: ['ngModel', '^?form'],
+    require: 'ngModel',
     controller: NgModelController,
-    link: function(scope, element, attr, controllers) {
-      var modelController = controllers[0],
-          formController = controllers[1];
-
-      if (formController) {
-        formController.registerWidget(modelController, attr.name);
-      }
+    link: function(scope, element, attr, ctrl) {
+      // notify others, especially parent forms
+      scope.$emit('$newFormControl', ctrl);
 
       forEach(['valid', 'invalid', 'pristine', 'dirty'], function(name) {
         scope.$watch(function() {
-          return modelController[name];
+          return ctrl[name];
         }, function(value) {
           element[value ? 'addClass' : 'removeClass']('ng-' + name);
         });
       });
 
       element.bind('$destroy', function() {
-        scope.$emit('$destroy', modelController);
+        scope.$emit('$destroy', ctrl);
       });
     }
   };

test/directive/inputSpec.js

@@ -4,9 +4,11 @@ describe('NgModelController', function() {
   var ctrl, scope, ngModelAccessor;
 
   beforeEach(inject(function($rootScope, $controller) {
+    var attrs = {name: 'testAlias'};
+
     scope = $rootScope;
     ngModelAccessor = jasmine.createSpy('ngModel accessor');
-    ctrl = $controller(NgModelController, {$scope: scope, ngModel: ngModelAccessor});
+    ctrl = $controller(NgModelController, {$scope: scope, ngModel: ngModelAccessor, $attrs: attrs});
 
     // mock accessor (locals)
     ngModelAccessor.andCallFake(function(val) {
@@ -27,6 +29,8 @@ describe('NgModelController', function() {
 
     expect(ctrl.formatters).toEqual([]);
     expect(ctrl.parsers).toEqual([]);
+
+    expect(ctrl.widgetId).toBe('testAlias');
   });